Transmitting-telephone



S. RUSSELL. Triansmitting Telephone. NQ. 240,041; Patented'Aprn 1'2, 188|.

I; h?" Il INVENTOR:

@om-mu u ATTEST N, PETERS, PHUTO-LITHOGRAPHER, WASHINGTON D C f STATES,

PATENT GFFIOE.

SAMUEL RUSSELL, or BROOKLYN, NEW YORK, ASSIGNORTO THE NATIONAL TELEPHONEOOMPANY, OE HARTFORD, OONNEcrIOUr.

TRANSM lTTlNG-TELEPHONE.

SPECIFICATIGN forming part of Letters Patent No. 240,041, dated April 12, 1881.` Application filed January 12, 1880.

To wll'iwhomit may concern:

Be it known that I, SAMUEL RUSSELL, of

Brooklyn, in thc'county of Kings and State of New York, have invented certain Improvements in Transmitting-Telephones, of which the following` is a specication.

My invention relates to .what are known as battery-transmitters, and has for its Object to increase the fidelity and volume of the transmitted sounds.

\ In the drawings, Figure 1 isa vertical midcase; B, a frame or bridge xed to the back thereof; C, the mouth-piece formed in the front thereof; D, the diaphragm, and E F the resistance-varying electrodes or contact-points. The electrode E is fixed to the 'back` of the diaphragm and borne thereby, and the electrode F is. sustained by a springer springs, b, which act to press the. electrode F lightly against the electrode E, this pressure being adjustable. The action is toproduce undulations in a battery-current passed through the contacts, which undulations correspond to the vibrations of the diaphragm, in the manner common to all transmitting-telephones.

I have thus .far described only the common form of battery-transmitter, to which` Ilay no claim, and I will now set forth my novel improvements thereon.

The electrode F is borne by a spring or springs, b, which are fixed to a slide, o, (being a sliding plunger or frame,) which is arranged to slide'in bearin gs in the, frame B in a direction toward or from the diaphragm. For adjustin g the pressure of the electrode F against the electrode E, I provide alever, c, fulcrumed lto the frame B, engaging the rod c, and its eX- tremity depressed by a th umbscrew,f, against the upward pressure of a spring, g. By this means a very accurate adjustment can be given to the electrodes.

In Figs. 4 and 5 I have shown two modifications of the adjusting device, which may be substituted for that shown in Fig. l. if preferred. Fig. 5 shows a differential screw, f, which imparts vertical motion to a screwthreaded rod, c, which is iixed to a sliding cross-head, c', whereby it is held from revolv ing, and to this cross-head is attached a leafspring, b, which bears the cup c. Fig. 4 shows a horizontal Screw,f, which engages a threaded sleeve orfemale screw forming the top of the electrode-bearing slide c. The contacting surfaces ofthe electrodes F and E are beveled, so that the lateral movement of the former on the latter will press them closely together.

Heretofore it has been com mon to incase the edge or periphery of the diaphragm. in a rubber ring whichextends down over both faces fora short distance, and then to place it in a shallow recess in the rearV face or side of the block4 A, and fasten it therein by means of clips similar to those marked It 71J in Figs. 2 and 6.

By this meansnearly all vibration at or near the edge hasV been deadened,which, as I believe, has materially impaired its ability to transmit sounds with the desired power and clearness. To overcome this defect I fasten the diaphragm at as few points as possiblesay three or four-and leave it free to vibrate in the spaces between the clamping-points. I take short strips t' t', of rubber or analogous material, and bend them over the edge ofthe diaphragm at intervals, then place the diaphragm in the recess and screw down theclips h-h over the rubber strips, as best shown in Figs. 2 and 6. Thus at each clam ping-point the r edge of the diaphragm is confined between two elastic cushions.

I am aware that adiaphragrn has been heretofore confined at a ser-ies of points around its edge; but the means of clamping have consisted of naked metal surfaces, which practically prevent all vibration of the diaphragm at the clamping-points, besides causing the generation pf extraneous and confusing sounds, resulting from the friction of the diaphragm against the edges of the metal.

In order to control to some extent the amplitude of the vibrations of the diaphragm,V whereby any timbre or sympathetic sound peculiar to itself may be suppressed, I provide an adjustable damper, which I will now describe.

Referring to Fig. 1, H is a leaf-spring, xcd

IOO

at one end to some stationary part, and at the other end arranged in contact with a depressing-screw, I. At about its middle the spring H is curved toward the center of the diaphragm, and between the two is placed an an nular pad or washer, J, of rubber or other elastic material. The electrode E projects up through the central openingin the pad J, and through a corresponding aperture formed in the spring H. By turning the screw I the pressure of the spring H upon the pad can' be adjusted.` If preferred, an adjusting-screw, I, may be arranged at each end of the spring.

In Fig. 7 the spring H is shown attached to the block A, instead of to the frame B; and in Fig. 4 an O-shaped spring is shown, its ends brought nearly together and fixed to the top of the frame B, and having\two adjustingscrews, I I, arranged horizontally in the sides of the frame B. By causing the screws I I to approach each other the center of the spring H is forced down upon the pad J.

I am aware that in a transmitting-telephone having two parallel diaphragms with the resistance-varying device between them springs have been arranged to press against a rubber cushion on the center of each diaphragm, in order to hold the latter in place, the spring connected with the mouth-piece diaphragm being incapable of adjustment, and the other spring being adjustable by means of a screw, (similarly to my modification shown in Fig. 7,) in order to regulate the tension upon the resistance-varying device; but I am not aware that such spring and. cushion have been employed in a telephone for muffling the vibrations of the mouth-piece diaphragm, for which purpose I consider it essential that the pressure of the spring shall be adjustable. In the telephone referred to the entire edge of the diaphragm is held against a continuous cushion, instead of being supported at intervals only, as in mine, in which latter case the einployment ofthe damper 'is specially desirable.

I do not, in this application, make any specific claims to the forms of my invention shown in Figs. 4 and 5, but reserve to myself the right to make these the subjects of separate applications for patents hereafter.

I claim as my invention- 1. A telephone wherein the diaphragm is confined at separate points around its periphery between two layers of elastic material, leaving the intervening portions of its edge unsupported and free to vibrate, substantially 'as and for the purposes set forth.

2. In a transmitting-telephone, the combination of the diaphragm D, the electrode E borne thereby, the electrode F fixed in a holder, a, with the springs b and adjustable slide c, arranged behind said electrode, substantially as set forth.

3. The combination, in a transmitting-telephone, of the supporting-block A, the diaphragm D fixed thereto, the electrode E borne thereby, the electrode F fixed in the holder a, the frameB, the slide c, suitable means for adjusting it, and the bearingsprings b connecting said holder a to said slide c, substantially as set forth.

4. The combination, in a transmitting-telephone, of the mouth-piece, the diaphragm arranged behind the same and supported at its edges, an elastic cushion arranged behind the diaphragm at or around its center, a spring arranged to press upon said cushion and force it against the diaphragm, and means for adjust-ing the tension of said spring, substantially as and for the purposes set forth.

5. In a transmittin g-telephone, the combination of a diaphragm supported elastically at separate points around its edge, the intervening portions of its edge being left unconned and free to vibrate, with a damper to control its vibration, consisting of an elastic cushion at its center and an adjustable spring arranged to press against said cushion, substantially as set forth.

6. The combination of the diaphragm, the electrode E borne thereby, and the electrode F, with its holder a, the spring or springs b b, slide c, the lever e, the screw f, and the spring g, forming an adjusting device for the'electrode F, substantially as set forth.

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

SAMUEL RUSSELL.

Witnesses ARTHUR C. FRASER, HENRY OoNNET'r. 

